Understanding the 3 Heat Pump Options for Your Massachusetts Home

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| Published:March 21, 2014

If your HVAC equipment needs to be replaced, considering heat pump options might help you find a system that offers both convenience and energy savings. The options include air-source, ground-source and absorption heat pumps. All heat pumps operate on the same principle of moving heat energy instead of generating it.

Heat pumps are rated for both cooling and heating efficiency. The minimum cooling efficiency rating stands at 13 SEER (seasonal energy efficiency ratio) and 7.7 HSPF (heating season performance factor). In our cold-winter climate, it probably makes more sense to prioritize HSPF when shopping for a heat pump.

Characteristics of the three heat pump varieties include:

Air-Source Heat Pumps

These use the air as the medium for heat transfer. In the winter, they extract the heat from the air outdoors, and using refrigerant, carry heat energy inside to be extracted for indoor heating.

In the cooling mode, they use a reversing valve to switch the refrigerant flow. Heat is absorbed from the inside air as a fan blows across the evaporator coil, which creates cooler air inside. Refrigerant removes the heat energy outside to be released into the air. These heat pumps can lose efficiency when the outside air gets cold, though they typically have backup heating elements that kick on when the temperatures fall below freezing.

Ground-Source Heat Pumps

Also referred to as geothermal systems, these are the most energy efficient of all the heat pump options because they use the stored solar energy underground to extract or deposit heat. Temperatures below the frost line are much warmer in the winter and cooler in the summer, which contributes to their efficiency. Ground-source heat pumps use a loop field with a life expectancy is 50 years or more. The rest of the heat pump sits inside and with routine maintenance can last 25 years or more. Ground-source systems don’t use an outdoor condenser, making them exceptionally quiet.

Absorption Heat Pumps

Used primarily in commercial buildings, these are now available for homes larger than 4,000 square feet, according to the U.S. Department of Energy. They’re good choices for homes off the grid because they use natural gas, propane or solar as the energy source.